ERBB2 and breast cancer: The SOPHIA trial demonstrated that in patients with metastatic HER2-positive breast cancer who had previously received anti-HER2 therapy, the chimeric antibody margetuximab + chemotherapy, over trastuzumab + chemotherapy, improved progression-free survival (PFS) with a median of 5.7 months vs. 4.4 months, median OS with 21.6 months vs. 19.8 months, and objective response rate with 25% vs. 14%, accompanied by comparable safety [53].